The strength of brightness illusion in an Ehrenstein figure has been examined as a function of two variables—inducing line length and gap size—by a two-alternative forced-choice procedure. The results show an interaction between the two variables; the length of the inducers and gap size are both involved in the formation of the brightness illusion, with gap size as the stronger factor. A spatial limit (corresponding to a gap size of 2.4 deg) was found, below which the illusion is always present regardless of the length of the inducers. An area ratio, defined as the ratio of the area of the ring formed by the four inducing lines of an Ehrenstein figure to the area of the illusory surface, takes into account the different spatial factors studied in the experiment and the global size of the Ehrenstein figure. The strength of the illusion was found to increase linearly with increasing values of the area ratio.
Get full access to this article
View all access options for this article.
References
1.
BantonTLeviD, 1992“The perceived strength of illusory contours”Perception & Psychophysics52676–684
2.
CorenS, 1972“Subjective contour and apparent depth”Psychological Review79359–367
3.
CornsweetT N, 1970Visual Perception (New York: Academic Press)
4.
Deters-BruggemannHMeinhardtG, 1994“A hysteresis model for the temporal dynamics in the Ehrenstein illusion”Perception23Supplement, 103–104
5.
DrespB, 1992“Local brightness mechanisms sketch out surfaces but do not fill them in: Psychophysical evidence in the Kanizsa square”Perception & Psychophysics52165–170
6.
DrespB, 1993“Bright lines and edges facilitate the detection of small light targets”Spatial Vision7213–225
7.
DrespBLorenceauJBonnetC, 1990“Apparent brightness enhancement in the Kanizsa square with and without illusory contour formation”Perception19483–489
8.
DrespBSalvano-PardieuVBonnetC, 1996“Illusory form inducers of opposite contrast polarity: Evidence for multi-stage mechanisms of integration”Perception & Psychophysics58111–124
9.
DumaisS TBradleyD R, 1976“The effects of illumination level and retinal size on the apparent strength of subjective contours”Perception & Psychophysics19339–345
10.
EhrensteinW, 1941/1987“Ueber Abwandlungen der L. Hermannschen Helligkeitserscheinung”Zeitschrift für Psychologie15083–91 [English translation by HoggA, “Modification of the brightness phenomenon of L Hermann”, in PetryMeyer (1987) pp 35–39]
11.
FrisbyJClatworthyJ, 1975“Illusory contours: Curious case of simultaneous brightness contrast”Perception4349–357
12.
FuldKO'DonnellK, 1984“Brightness matching and scaling of the Ehrenstein illusion”, in Sensory Experience, Adaptation and Perception Eds SpillmannLWootenB R, (Hillsdale, NJ: Lawrence Erlbaum Associates) pp 461–469
13.
GerritsH J MVendrikA J H, 1970“Simultaneous contrast, filling-in process and information processing in man's visual system”Experimental Brain Research72279–286
14.
GoveAGrossbergSMingollaE, 1995“Brightness perception, illusory contours, and cortico-geniculate feedback”Visüal Neüroscience121027–1052
15.
GrossbergS, 1994“3-D vision and figure - ground separation by visual cortex”Perception & Psychophysics5548–120
16.
GrossbergSMingollaE, 1985“Neural dynamics of form perception: Boundary completion, illusory figures and neon color spreading”Psychological Review92173–211
JoryM, 1987“Increment thresholds in illusory contour line patterns”, in PetryMeyer (1987) pp 81–90
20.
JoryMDayR H, 1979“The relationship between brightness contrast and illusory contours”Perception83–9
21.
KellmanPLoukidesM, 1987“An object perception approach to static and kinetic subjective contours”, in PetryMeyer (1987) pp 151–164
22.
KennedyJ, 1976“Sun figure: An illusory diffuse contour resulting from an arrangement of dots”Perception5479–481
23.
KennedyJ, 1978“Illusory contours and the end of lines”Perception7605–607
24.
KennedyJ, 1981“Illusory brightness and the end of petals: Change in brightness without aid of stratification or assimilation effects”Perception10583–585
25.
LesherG, 1995“Illusory contours: Toward a neurally based perceptual theory”Psychonomic Bülletin and Review131–50
26.
LesherGMingollaE, 1993“The role of edges and line-ends in illusory contour formation”Vision Research332253–2270
27.
ParksT, 1981“Subjective figure: An infrequent, but certainly not unprecedent, effect”Perception10589–590
28.
ParksT, 1987“On the relative frequency of depth effects in real versus illusory figures”Perception & Psychophysics42333–336
29.
PeterhansEvon der HeydtR, 1989“Mechanisms of contour perception in monkey visual cortex. II: Contours bridging gaps”Joürnal of Neüroscience91749–1763
30.
PeterhansEvon der HeydtRBaumgartnerG, 1986“Neuronal responses to illusory contour stimuli reveal stages of visual cortical processing”, in Visüal Neüroscience Eds PettigrewJ DSandersonKLevickW, (Cambridge: Cambridge University Press) pp 343–351
31.
PetrySHarbeckAConwayJLeveyJ, 1983“Stimulus determinants of brightness and distinctness of subjective contours”Perception & Psychophysics34169–174
32.
PetrySMeyerG, (Eds), 1987The Perception of Illüsory Contoürs (New York: Springer)
33.
PrazdnyK, 1983“Illusory contours are not caused by simultaneous brightness contrast”Perception & Psychophysics34403–404
34.
SambinM, 1985“Figure anomale: La misura dell'ampiezza di una disomogeneita indotta”, in Conoscenza e Strüttüra Festschrift per Gaetano Kanizsa, Ed.GerbinoW, (Bologna: Il Mulino) pp 437–452
35.
ShipleyT FKellmanP J, 1992“Strength of visual interpolation depends on the ratio of physically specified to total edge length”Perception & Psychophysics5297–106
36.
SiegelSPetryS, 1991“Evidence for independent processing of subjective contour brightness and sharpness”Perception20233–241
37.
SpillmannLDrespB, 1995“Phenomena of illusory form: Can we bridge the gap between levels of explanation?”Perception241333–1364
38.
SpillmannLFuldKNeumeyerC, 1984“Brightness cancellation and increment threshold in the Ehrenstein illusion”Perception13513–520
39.
SpillmannLWernerJ, 1996“Long range interaction in visual perception”Trends in Neurosciences19428–434
40.
WareCKennedyJ, 1977“Illusory line linking solid rods”Perception6601–602
41.
WatanabeTOyamaT, 1988“Are illusory contours a cause or a consequence of apparent differences in brightness and depth in the Kanizsa square?”Perception17513–521.
